cool as a cucumber.

A couple of phrases, that never really made sense to me:

Clean as a whistle-Whistles are not really that clean. You blow your spit into it, how can that be sanitary?

Sick as a dog- Are ALL dogs always sick?

Cute as a button-Why and how are buttons cute?

Clear as day-What if, its a cloudy, rainy day? that's not very clear.

Easy as pie, or something similiar, Piece of cake- It doesn't cross my mind as pie being "easy", or when describing how simple something was, it being a "piece of cake". Although, I am guilty for using that phrase before.

Poor as dirt. or "dirt poor"- Since when did dirt have the ability to be poor??

I don't know, these are just a few of misleading phrases that catch my attention when I hear them.

Any other phrases like these that don't make sense to you?